Field of the Invention
The invention relates to an arrangement for ventilating a room, in particular a laboratory room, according to the claims.
Building technology makes use, for the ventilation of research laboratories, for example, for chemical or physical research, of ceiling constructions in which the lines for air supply, air discharge and the technical gases required in the laboratory, liquids, electrical power and data lines, etc., are arranged on a carrier frame which is mounted on the building ceiling.
From WO 2007/033821, it is known in this context to secure the supply air channel for the supply of fresh air and the discharge air channel which is arranged over it above the passage region to a carrier frame, the supply air channel extending in the plane of the carrier frame and being occupied with swirl nozzles, from which the generally cooled supply air is locally discharged. The fresh air being discharged is provided with a strong rotation impulse and induces in the region of the centre of the swirl nozzle a large quantity of ambient air which is subsequently thrown to the side and leads to significant mixing of supply air and ambient air. This mixing ensures that the temperature and also the contaminants present are evenly distributed in the entire room in a short space of time. Draughts are thereby very easily produced; they are occasionally perceived by the users of the laboratory to be disruptive and often lead to impairment of health.
From DE 10 2010 006 360 A1 which was not previously published, it is further known to configure the supply air channel as a textile channel which is provided with microperforations and which is in the form of a horizontal “D” in cross-section and which is secured with the flat side to the lower side of the carrier frame. Although the risk of draughts of air, in particular at high air exchange rates of more than 8 air changes per hour and comparatively low supply air temperatures with respect to the ambient air, is significantly reduced compared with otherwise conventional arrangements owing to the perforation which is formed over a large area, the perforation of the textile channel over the entire cross-sectional width thereof involves the problem that the cool supply air is mixed with warm ambient air not only in the passage region, but also in the region of the work tables.
To be precise, with the textile, spring-like or laminar outlets described above, regardless of their form, an inverted droplet form of the discharged cold air is produced directly below the outlet. The fresh air thereby accelerates rapidly downward in a narrow band and reaches output speeds which, at the air exchange rates and supply air temperatures required in laboratories, lead to speeds which are far beyond the permissible maximum values and are perceived as a draught of air by the laboratory assistants.